Lifting jack



Mafch 1o, 1936. J, A ADELL 2,033,503

LIFTINFT JACK Filed June l. 1934 l5 Sheets-Sheet 1 6 if@ f@ ,72

J. A. ADELL March 10, 1936.

LIFTING JACK Filed June l. 1954 3 Sheets-Sheet 2 J, A. ADELL LIFTING JACK March 10, 1936.

` 3 Sheets-SheNet 3 Filed June l. 1934 Patented Mar. 10, 1936 UNITED STATES PATENT OFFICE LIFTING JACK Application June 1, 1934, Serial No. 728,568

15 Claims.

This invention relates to lifting jacks and particularly to double range screw jacks for use with automobiles.

It is the general object of my invention to provide a jack for such-purposes which is of an improved and simplified construction, light in weight and reliable in operation.

To the attainment of this object in the preferred form, I provide two sets of threaded elements mounted to successively engage the same lifting screw.

I also provide means for opening and closing one set of said threaded elements in predetermined relation to the vertical movement of the other set of threaded elements.

My invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of theinvention is shown in the drawings, in which Fig. 1 is a side elevation of my improved jac in closed position;

Fig. 2 is a similar view showing the jack in fully raised position;

Fig. 3 is a plan view of the jack;

Fig. 4 is a side elevation thereof; v

Fig. 5 is an enlarged sectional side elevation of certain parts of the jack;

Fig. 6 is a sectional plan view of the jack casing, taken along the line 6-6 in Fig. 4;

Figs. 7 and 8 are perspective views of the lifting members of the jack; v

Fig, 9 is a sectional end elevation, Ataken along the line '9 9 in Fig. 3;

Fig. 10 is an end elevation, partly in section, showing the jack in lan intermediate position, and Fig. 11 is a view similar to Fig. 10 but showing the jack fully raised.

My improved jack comprises a base or casing 20, a plunger 2| and intermediate lifting members 22. The base 2|] is preferably made with sheet metal side sections permanently secured together by rivets or welding and firmly .attached to an enlarged base plate 22a.

The casing 20 has a boss 23 (Fig. 5) at one side thereof, providing a bearing for a short shaft 24 on which a pinion 25 is mounted. The outer portion of the shaft 24 is squared as indicated at 2B for the application of a wrench or crank.

The teeth of the pinion 25 are specially formed lto engage openings in the upper surface of a disc gear 3| xed to the lower end of a lifting screw 32. The disc gear 3| is provided with a downwardly offset iiange 3 |a which increases the (o1. 25er-102,)

stiffness thereof. The disc gear 3| is mounted on a ball thrust bearing 33, thus insuring free and easy rotation of the lifting screw 32.

The bearing 33 is loosely centered in an opening in a plate 34 (Fig. 5) which limits its free sliding movement and the flange 3|a of the disc gear 3| is a loose running t within the lower portions 20a of the casing 2li. The lifting screw 32 thus has no fixed bearings and is to a considerable extent free to center itself with respect to the Vthreaded members which engage therewith.

The lifting plunger 2| (Fig. 7) is shown as being of substantially rectangular cross section and as being provided with a top or bearing plate 40 and with a threaded bottom member 4| (Figs. 7 and 9) rigidly secured within the member 2| by pins 42 or in any other suitable manner. When the jack is closed, the member 2| occupies the position shown in Fig. 9 and will be moved upward from closed position by rotation of the lifting screw 32.

The intermediate lifting members 22 are pivoted at 50 (Fig. '7) on a sleeve 5| which is freely slidable on the upper plunger 2|. Lugs 52 (Fig. 9) at the lower end of the plunger 2| engage notches Y53 in the lower edge of the sleeve 5| and thus limit relative downward movement of the sleeve, but the sleeve is free to slide upward the entire length of the plunger 2 I.

The intermediate members 22 are provided with half-nut portions 55 lat their lower ends, adapted to engage the lifting screw 32 when swung inward 'as will be hereinafter described.

Upper end portions of the members 22 are inwardly offset to provide shoulders 56 (Figs. 7 and 9) underlying the bottom edges of the plunger 2| and supporting the load when the jack is operating in the upper range of its movement. The shoulders 56 thus relieve the pivots 50 of the load which would otherwise act through the pivot bearings. Additional upper Yend portions 5l (Fig. 7) of the members 22 are outturned to engage abutments 58 (Figs. 6 and 9) in the upper portion of the casing 2|). By such engagement, downward movement of the members 22 is limited and the members 22 are swung apart to the position indicated in Figs. 7 and 9.

. The eXtreme upper end of the casing 20 may be provided with a reenforcing band 60 (Fig. 9) displaced outwardly as indicated at 6| to permit the portions 51 of the members 22 to move freely downward into engagement with the abutments 58.Y Y Recesses 62 (Fig. 8) in the sleeve 5| provide clearance for the upwardly projecting end portions 51 of the members 22 and portions 63 (Figs. 7 and 9) of the members 22 are displaced inwardly to engage the upper surfaces of the half nuts 55 and resist upward displacement thereof.

Vertical guideways 10 (Figs. 5 and 6) are formed in the upper portion of the casing and at one or both sides thereof, these guideways being indicated in broken lines in Figs. 9 and 10 and being adapted to receive flanges 1| (Figs. 7 and 10) on the intermediate members 22 as said members 22 move upwardly.

Having described the details of construction of my improved jack, the method of operation thereof is as follows:

Assuming that the parts are in the closed or nested position indicated in Figs. 1 and 9, the pinion 25 is manually rotated, turning the lifting screw 32 in the direction of the arrow a in Fig. 5 and acting through the threaded member 4| to raise the plunger 2| substantially to the position shown in Fig. 10.

As the plunger 2| reaches this raised position, the lugs 52 (Fig. 8) engage the sleeve 5| and cause the sleeve to move upward with the plunger 2|. Such upward movement raises the offset ends 51 (Fig. 9) from the abutments 58 and permits the intermediate members 22 to be swung inward by engagement with the sides of the casing 20 at the points 65 (Fig. 9).

The half nuts 55 are thus swung into operative position relative to the screw 32, as shown in Fig. 10, and continued rotation of the screw 32 raises the plunger 2| higher and causes the half nuts 55 to engage the thread of the lifting screw 32.

The shoulders 56 (Fig. 10) are then in lifting engagement with the lower edge of the plunger 2| and the intermediate members 22 thereafter continue the upward movement of the plunger 2| as it passes out of engagement with the screw 32.

As soon as this upward movement of the members 22 begins, the flanges 1| (Fig. 7) enter the guideways 10 (Fig. 6) and hold the half nuts 55 firmly in engagement with the screw 32. Continued rotation of the screw 32 thereupon raises the members 22 and plunger 2| to the fully elevated position shown in Figs. 2 and 11.

On lowering the jack, the described operation is reversed and the half nuts 55 are swung outward out of engagement with the screw 32 when the offset portions 51 engage the abutments 58 as shown in Fig. 9.

Just prior to such separation, the upper threaded member 4| again engages the screw 32.

I have thus shown an extremely simple construction in a double range lifting jack by which a single lifting screw is caused to operate successively with two sets of threaded elements associated respectively with the upper plunger 2| and with the intermediate members 22.

All parts are of rm and rigid construction and many of them are well adapted for production by sheet metal operations, with a resulting economy in manufacture.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed, otherwise than as set forth in the claims, but what I claim is 1. A lifting jack comprising a casing, a lifting screw rotatable therein, means to rotate said screw, a lifting plunger, a nut in said plunger engaged by said screw, intermediate members movable toward and from each other and with respect to which said plunger is slidable, half nuts on said intermediate members, and means to move said members to engage said half nuts with said lifting screw when said plunger is raised beyond a predetermined elevation.

2. The combination in a lifting jack as set forth in claim l in which said intermediate members and casing have cooperating portions effecting relative swinging movement of said intermediate members as said members are moved upward and downward.

3. The combination in a lifting jack as set forth in claim 1 in which said intermediate members are provided with shoulders and said casing is provided with abutments cooperating with said shoulders to separate said half nuts as said intermediate members are moved downward.

4. The combination in a lifting jack as set forth in claim l in which said intermediate members are provided with shoulders underlying and supporting said plunger when said half nuts engage said lifting screw.

5. A lifting jack comprising a casing, a plunger, u

a nut in said plunger, a lifting screw for said plunger, a member slidable on said plunger, means to limit such sliding movement, arms pivoted to said sliding member, half nuts on said arms, and means to move said arms and half nuts to cause said half nuts to engage said lifting screw as said sliding member receives initial upward movement by said plunger.

6. A lifting jack comprising a casing, a plunger, a nut in said plunger, a lifting screw for said plunger, a member slidable on said plunger, means to limit such sliding movement, arms pivoted to said sliding members, half nuts on said arms, and means to move said arms and half nuts to cause said half nuts to engage said lifting screw as said sliding member receives initial upward movement by said plunger and before said plunger and screw are disengaged.

'7. A lifting jack comprising a casing, a plunger, a nut in said plunger, a lifting screw for said plunger, a member slidable on said plunger, means to limit such sliding movement, arms pivoted to said sliding members, half nuts on said arms, means to move said arms and half nuts to cause said half nuts to engage said lifting screw as said sliding member receives initial upward movement by said plunger, and means to lock said half nuts together during continued upward movement thereof by said screw.

8. A lifting jack comprising a casing, a plunger, intermediate lifting members, a sleeve slidable on said plunger and to which said intermediate members are pivoted, a nut in said plunger, half nuts in said intermediate members, a lifting screw in said casing, and means to close said half i nuts on said screw as said nut approaches the upper end of said lifting screw.

9. A lifting jack comprising a casing, a plunger, intermediate lifting members, a sleeve slidable on said plunger and to which said intermediate members are pivoted, a nut in said plunger, half nuts in said intermediate members, a lifting screw in said casing, and means to close said half nuts on said screw as said nut approaches the upper end of said lifting screw, said sleeve and plunger having cooperating portions limiting downward movement of said sleeve relative to said plunger.

l0. A lifting jack comprising a casing, a plunger, intermediate lifting members, a sleeve slidable on said plunger and to which said intermediate members are pivoted, a nut in said plunger, half nuts in said intermediate members, a lifting screw in said casing, means to close said half nuts on said screw as said nut approaches the upper end of said lifting screw, and means to lock said half nuts against separation during continued upward movement thereof by said screw.

11. A lifting jack comprising a casing, a plunger, intermediate lifting members, a member slidable on said plunger and to which said intermediate members are pivoted, a nut in said plunger, half nuts in said intermediate members, a lifting screw in said casing, and means to close said half nuts on said screw as said nut approaches the upper end of said lifting screw, said casing having vertical guideways and said intermediate members having anges slidable in said guideways to hold said half nuts from separation during further upward movement thereof.

12. In a lifting jack, a casing having a base, a lifting screw, a disc gear for said screw, and a thrust bearing for said screw and gear, a plate for supporting said bearing having an opening therethrough larger than the bearing, said bearing extending through the opening to give it a limited free sliding movement relative to said base, and said disc gear having a peripheral flange loosely centered by said casing.

13. A lifting jack including a casing, a threaded member rotatable therein, means to rotate said member, a lifting element associated with said threaded member, a second lifting means laterally movable into and out of engagement with said threaded member, and inclined cam surface for moving said second means into engagement with said threaded member when said lifting element is in a predetermined position.

14. A lifting jack including a casing, a rotatable member therein, means to rotate said member, a lifting element having a portion engaging said rotatable member, a slidable member associated with said lifting element, a second lifting means including channel shaped elements pivoted to said slidable member and having portions engageable with said rotatable member, and means to move said channel shaped elements into engagement with said rotatable member when sai-d rst mentioned lifting element has been extended from said casing.

15. In a lifting jack, the combination of a casing, a rotatable screw, means to rotate said screw, a lifting element cooperating with said screw, a sleeve cooperative with said lifting element, a second lifting element pivotally coupled to said sleeve and having threaded portions movable into contact with said screw, and stop means on lifting element into contact with said screw.

J OHN A. ADELL. 

